Disable auto user creation and provide a way to bootstrap user creation for local testing.

If you call the backend json apis with an unregistered user you will get a 400 error with the UNREGISTERED_USER error type.

    [INFO]   ErrorResponseMsg(error=ErrorResponseMsg.ErrorInfo(message=User registration is required, type=UNREGISTERED_USER, stackTrace=null))

Every time you run "mvn clean" on localhost you will have to go to this page:

    http://localhost:8080/bootstrap/

Then click on "Boostrap current user". That will create the user. And show you "/api/me" so you can see the new user.

The page also has a button to "Boostrap test resources". A UI shortcut for "/bootstrap/test_resources".

After that everything should work as it did before.